Background: Attention Bias Modification Treatment (ABMT) is a newly emerging, promising treatment for anxiety disorders. Although recent randomized control trials (RCTs) suggest that ABMT reduces anxiety, therapeutic effects have not been summarized quantitatively.Methods: Standard meta-analytic procedures were used to summarize the effect of ABMT on anxiety. With MEDLINE, January 1995 to February 2010, we identified RCTs comparing the effects on anxiety of ABMT and quantified effect sizes with Hedge's d.Results: Twelve studies met inclusion criteria, including 467 participants from 10 publications. Attention Bias Modification Treatment produced significantly greater reductions in anxiety than control training, with a medium effect (d = .51 [corrected] (p < .001). Age and gender did not moderate the effect of ABMT on anxiety, whereas several characteristics of the ABMT training did.Conclusions: Attention Bias Modification Treatment shows promise as a novel treatment for anxiety. Additional RCTs are needed to fully evaluate the degree to which these findings replicate and apply to patients. Future work should consider the precise role for ABMT in the broader anxiety-disorder therapeutic armamentarium.